Natural radioelement solution by circulating ground waters in the Stripa granite
- Univ. of Bath (England)
Natural radioelement concentrations in ground waters from the fracture flow regime in the Stripa granite were monitored during the period 1977-1986. Uranium concentrations from depths of 80 m or less and in mine waters from above the hydraulic sink produced by the deepest mining level (410 m), range from 10 to 90 ppb. {sup 234}U/{sup 238}U activity ratios are characteristic of chemical leaching processes at the shallower depths whilst at about 350 m ground waters occur which have an additional component of {sup 234}U by alpha-recoil processes. At greater depths, U concentrations are indicative of the changed redox conditions and are subject to activity ratio enhancement by the alpha-recoil process. Groundwater residence times may be estimated from the rate of such recoil solution of {sup 234}U in zones where chemical leaching of U is not active. The {sup 222}Rn contents of the mine waters are extremely high and can be related to the {sup 222}Rn flux from fracture surfaces and the fracture width. The fracture apertures range from 10 mm for the shallow groundwater zone ({sup 222}Rn contents < 400 Bq kg{sup {minus}1}) to 20 {mu}m for water from the deepest borehole section ({sup 222}Rn content 100 kBq kg{sup {minus}1}). The activity ratios {sup 234}Th/{sup 238}U, {sup 210}Pb/{sup 222}Rn and {sup 210}Po/{sup 222}Rn have been used to estimate residence times for Th, Pb and Po isotopes. Solution of Ra is controlled by chemical rather than alpha-recoil processes. The {sup 226}Ra content of the groundwater increases with salinity and is well correlated with groundwater Ca content. The {sup 228}Ra/{sup 226}Ra activity ratios in the ground waters suggest that water/rock interaction occurs predominantly with the average granitic matrix rather than with highly uraniferous fracture mineralization.
- OSTI ID:
- 7079371
- Journal Information:
- Geochimica et Cosmochimica Acta; (USA), Vol. 53:8; ISSN 0016-7037
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
29 ENERGY PLANNING
POLICY AND ECONOMY
58 GEOSCIENCES
GROUND WATER
GEOCHEMISTRY
RADIOISOTOPES
ROCK-FLUID INTERACTIONS
RADIOACTIVE WASTE FACILITIES
RESEARCH PROGRAMS
SITE CHARACTERIZATION
RADIONUCLIDE MIGRATION
MONITORING
SWEDEN
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CONCENTRATION RATIO
GRANITES
HIGH-LEVEL RADIOACTIVE WASTES
HYDROLOGY
ISOTOPE RATIO
LEACHING
LEAD 210
POLONIUM 210
RADIOACTIVE WASTE DISPOSAL
RADON 222
REDOX REACTIONS
RISK ASSESSMENT
SITE SELECTION
THORIUM 234
URANIUM 234
URANIUM 238
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHEMICAL REACTIONS
CHEMISTRY
DAYS LIVING RADIOISOTOPES
DISSOLUTION
ENVIRONMENTAL TRANSPORT
EUROPE
EVEN-EVEN NUCLEI
HEAVY ION DECAY RADIOISOTOPES
HEAVY NUCLEI
HYDROGEN COMPOUNDS
IGNEOUS ROCKS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LEAD ISOTOPES
MAGNESIUM 28 DECAY RADIOISOTOPES
MANAGEMENT
MASS TRANSFER
MATERIALS
NANOSEC LIVING RADIOISOTOPES
NEON 24 DECAY RADIOISOTOPES
NUCLEAR FACILITIES
NUCLEI
OXYGEN COMPOUNDS
PLUTONIC ROCKS
POLONIUM ISOTOPES
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
RADON ISOTOPES
ROCKS
SCANDINAVIA
SEPARATION PROCESSES
THORIUM ISOTOPES
URANIUM ISOTOPES
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES
WATER
WESTERN EUROPE
YEARS LIVING RADIOISOTOPES
052002* - Nuclear Fuels- Waste Disposal & Storage
540330 - Environment
Aquatic- Radioactive Materials Monitoring & Transport- (1990-)
540350 - Environment
Aquatic- Site Resource & Use Studies- (1990-)
290300 - Energy Planning & Policy- Environment
Health
& Safety
580000 - Geosciences